Age and multivariate-adjusted RR for the association of smoking status with the risk of PsA among all participants*
| Cases | Person-years | Age-adjusted RR (95% CI) | Multivariate-adjusted RR† (95% CI) | |
|---|---|---|---|---|
| Reference: never smokers | 76 | 865 189 | 1.00 | 1.00 |
| Smoking status | ||||
| Past smokers | 46 | 309 749 | 1.55 (1.07 to 2.23) | 1.54 (1.06 to 2.24) |
| Current smokers | 35 | 129 032 | 3.08 (2.06 to 4.61) | 3.12 (2.07 to 4.69) |
| 1–14 cigarettes/day | 12 | 62 479 | 2.19 (1.19 to 4.02) | 2.34 (1.27 to 4.33) |
| ≥15 cigarettes/day | 23 | 66 553 | 3.92 (2.45 to 6.27) | 3.77 (2.35 to 6.06) |
| p for trend | <0.0001 | <0.0001 | ||
| Duration, years | ||||
| <25 | 55 | 366 471 | 1.68 (1.19 to 2.38) | 1.70 (1.19 to 2.42) |
| ≥25 | 26 | 72 310 | 3.20 (2.02 to 5.07) | 3.12 (1.96 to 4.97) |
| p for trend | <0.0001 | <0.0001 | ||
| Pack-years | ||||
| <20 | 44 | 342 974 | 1.43 (0.99 to 2.08) | 1.48 (1.02 to 2.16) |
| 20–44 | 34 | 91 129 | 3.67 (2.42 to 5.56) | 3.33 (2.19 to 5.06) |
| ≥45 | 3 | 4678 | 4.53 (1.41 to 14.56) | 3.91 (1.21 to 12.59) |
| p for trend | <0.0001 | <0.0001 | ||
↵* Psoriasis cases with only skin phenotypes were excluded during the follow-up.
↵† Adjusted for age (continuous variable), body mass index (<18.5, 18.5–24.9, 25–29.9, 30–34.9 or ≥35 kg/m2), alcohol drinking (no, <4.9, 5.0–9.9, 10–14.9, 15–29.9 or ≥30.0 g/day), vigorous physical activity (metabolic equivalent h/week, in quintiles).
PsA, psoriatic arthritis.